Hypoxanthine in diagnosis, prognosis and pathogeny of hypoxic injury.

Oxypurines (hypoxanthine + xanthine, HX) were measured polarographically in the mixed umbilical cord blood plasma, the maternal venous blood plasma and in the anterior amniotic fluid of 104 deliveries. The HX increase was found in groups with clinical signs of perinatal hypoxia. The HX concentration in the mixed umbilical plasma above 15 umol/l (i.e., means +/- 2 S.D.) should be considered as pathological. The following results of experiments on animals suggested a possible pathogenic significance of xanthine oxidase (XOD) reaction on hypoxic injury: The higher the plasma XOD activity of different species (guinea pig, hamster, rat, mouse) the shorter was the survival time of the species in the interrupted hypoxia. Administration of hypoxanthine decreased the survival time of rats in the interrupted hypoxia, while the administration of allopurinol increased it. Allopurinol suppressed the post-hypoxic autoimmune response of the rats to brain tissue.